Kata'ib Hezbollah (Arabic: كتائب حزب الله‎, Brigades of the Party of God^[32]) or Hezbollah Brigades is an Iraqi Shia paramilitary group that is supported by Iran.^[33] It has been active in the Iraqi Civil War^[34] and the Syrian Civil War.^[35] During the Iraq War, the group fought against American invasion forces.^[32][36]

The group's structure is secretive, but Abu Mahdi al-Muhandis, an adviser to Iran's Quds Force and former Badr Organization member, is known to be a senior figure in the group.^[3][37] The group receives training and funding from the Quds Force.^[32][36] The US State department also claimed Lebanon-based Hezbollah provided weapons and training for the group.^[38] It came to prominence in 2007 for attacks against American and coalition forces,^[32][39] and was known for uploading its videos of attacks on American forces on the internet.^[40]

In Summer 2008 US and Iraqi Forces launched a crackdown against Kata'ib Hezbollah and the "Special Groups", the US military term for Iran-backed militias in Iraq. At least 30 of its members were captured during those months. Many of the group's leaders were captured and US officials claimed that "as result much of the leadership fled to Iran".^[41][42]

On 2 July 2009 the group was added to the U.S. State Department list of Foreign Terrorist Organizations. The group was held responsible for numerous IED bombings, mortar, rocket and RPG attacks as well as sniper operations, targeting US and Iraqi Forces and the Green Zone, including a November 2008 rocket attack that killed two U.N. workers.^[39]

In December 2009, the group intercepted the unencrypted video feed of MQ-1 Predator UAVs above Iraq.^[43]

12 February 2010 a firefight with suspected members of Kata'ib Hezbollah occurred 265 km (165 mi) southeast of Baghdad in a village near the Iranian border, the U.S. military said. Twelve people were arrested, it said. "The joint security team was fired upon by individuals dispersed in multiple residential buildings ... members of the security team returned fire, killing individuals assessed to be enemy combatants," the military said in a statement. The Provincial Iraqi officials said many of the dead were innocent bystanders, and demanded compensation. They said eight people were killed.^[44]

On 13 July 2010 General Ray Odierno named Kata'ib Hezbollah as being behind threats against American bases in Iraq. "In the last couple weeks there's been an increased threat ... and so we've increased our security on some of our bases," Odierno told reporters at a briefing in Baghdad.^[45]

In July 2011, an Iraqi intelligence official estimated the group's size at 1,000 fighters and said the militants were paid between $300 to $500 per month.^[46][47]

In July 2019, Principal Deputy Assistant Secretary of State for Near Eastern affairs, Joan Polaschik, stated "rogue" Iranian-backed militias plan operations that could kill Americans, coalition partners and Iraqis and U.S. diplomatic facilities and continue to conduct indirect fire attacks. This led the U.S. to remove non-emergency staff from its embassy in Baghdad and close its consulate in Basra.^[48] At the same hearing, Deputy Assistant Secretary of Defense for the Middle East Michael Mulroy said that Iran's "cynical interference" undermines Iraqi interests by supporting to non-compliant militias, more loyal to Tehran than Baghdad, undermining the Iraqi prime minister's authority, preying on ordinary Iraqis by crime and destabilizing the fragile communities liberated from ISIS.^[48]

In 2013 Kata'ib Hezbollah and other Iraqi Shia militias acknowledged sending fighters to Syria to fight alongside forces loyal to President Bashar al-Assad, against the Sunni rebels seeking to overthrow him in the Syrian Civil War.^[35]

Wathiq al-Batat, a former Kata'ib Hezbollah leader, announced the creation of a new Shia militia, the Mukhtar Army, on 4 February 2013, saying its aim is to defend Shiites and help the government combat terrorism.^[49]

In 2014 the group began taking a role in the fight against ISIL in Iraq.^[34] Also in 2014, they and six other predominantly Shia Iraqi paramilitary groups formed the Popular Mobilization Forces (PMF).^[50] Since October 2016, Kata'ib Hezbollah along with the Iraqi army and other PMF has taken part in the Battle of Mosul against ISIL.^[51] They have been, alongside other PMF, active in fighting around Tal Afar, severing ISIL's link from Mosul and Tal Afar to the rest of their territory.^[52]